But so many top athletes are using them – David Beckham, Kevin Pietersen, Rubens Barichello and half the PGA golf tour – that it’s difficult to dismiss them.

More after the break

“They helped me massively in the gym,” says Darren Bent. “I’ve worn them in games and they really seem to work. You feel like you’ve got more inner strength. It’s an alternative method and I’m into trying these things.”

So convinced is Bent, that he got his former Sunderland team-mates Jordan Henderson, Asamoah Gyan, Anton Ferdinand and Michael Turner donning them, too.

“Almost everything has a frequency inherent to it,” runs the company’s blurb. “Some react positively with your body and others negatively. When the hologram comes into contact with your energy field, it allows your body to interact with the natural, beneficial frequency stored within the hologram.”

The feelgood factor may be a placebo, but Bent is certainly convinced. “It can also give you a psychological edge – there’s no better feeling than feeling good on the pitch,” he says. Amen to that.